Clock distribution helps nodes in the network latch on to the nearest available clock source. The clock source provides the nodes with clocking information. Nodes represent switching points, such as switches or routers, within a network. The clock information of individual nodes is propagated into the network through a network clock distribution protocol (NCDP). On receiving NCDP topology messages, each node computes the spanning tree to find the appropriate root for the clock source. The introduction of private network-node interface (PNNI) increases the number of nodes in the network exchanging clock information. When NCDP is run on all the nodes, the topology information to be processed on a single node is huge. The system also frequently exchanges topology clock information with other peer nodes causing performance degradation and clock degradation.
The NCDP is represented graphically by a NCDP spanning tree. One embodiment of a typical NCDP spanning tree is illustrated by the network of FIG. 1. A series of nodes 100 are connected together in a network. A few of the individual nodes 110 in the network are connected to a clock source 120. In some instances, a node 110 may be connected to more than one clock source 120. The nodes 110 read clock information from the clock source 120. Those nodes 110 attached to a clock source 120 transmit the clock information to the nodes 100 without a clock source 120. This clock information is transmitted through out the network.